A Passive Optical Network (PON) system enables the shared use of fiber for services such as data, voice and video over between a central office and service subscriber sites. A PON system is relatively inexpensive to deploy and operate due to the compact size and passive nature of much of the equipment comprised by the PON system facilities. For example, a passive optical splitter that fans fiber out to service subscribers in a PON system is relatively small, uses no electronics and requires no power source.
Current and emerging PON systems offer cost-effective, end-to-end solutions that are capable of delivering a combination of high-demand services. Specific examples of such current and emerging PON systems include Broadband PON (BPON), Ethernet PON (EPON) and Gigabit PON (GPON). Examples of services that can be provided via such PON systems include various types of telephony services, data transmission services and video services. Signals for such services are transported optically from the central office (CO) or headend (HE) to an optical-network termination unit (ONT) at a service subscriber's site. The ONT is configured to provide optical network termination functionality and, in some implementations, to also provide conventional network interface device functionality.
Conventional Bi-Directional PON solutions (e.g., in accordance with International Telecommunication Union (ITU) standard G.983, ITU standard G.984 and Institute of Electrical and Electronics Engineers (IEEE) standard 802.3ah) provide for a backbone fiber, which is deployed from a serving source. An optical line terminal (OLT) at the CO is an example of such a servicing source. The backbone fiber extends to a distribution point where, typically, an optical splitter is employed for connecting branch fibers between the backbone fiber and multiple ONTs. In such a conventional arrangement, each one of the ONTs comprises respective optical front-end components for facilitating interface functionality with a signal carried by the respective branch fiber.
The arrangement of optical splitters and ONTs comprising respective optical front-end components in conventional PON systems is known to present a number of drawbacks. For one, an abundance of optical components at the far end of a backbone fiber adversely impacts reliability. The number of optical components required for interfacing with ONTs in a conventional PON system (e.g., optical splitters and optical front-end component of ONTs) is proportional to by the number of ONT's being served, thus increasing the potential for downtime and the need for service calls. Another drawback is the inherent cost associated with implementing and maintaining such optical component required for interfacing with ONTs. Similar to reliability, deployment and maintenance costs are directly impacted by the number of optical component required for interfacing with ONTs in a conventional PON system. As previously mentioned, each ONT in a conventional PON system comprises respective optical front-end components for facilitating interface functionality with a signal carried by the respective branch fiber, thus directly impacting deployment and maintenance costs.
Therefore, facilitating transmission of optical signals in a manner that overcomes drawbacks associated with conventional ONTs in a PON system would be novel, advantageous and useful.